1. Field of the Invention
The present invention relates to an X-ray diagnosis apparatus and image processing apparatus which generate image data set concerning perfusion.
2. Description of the Related Art
A capillary vessel image visualizes perfusion in capillary vessels of cerebral blood vessels. In, for example, cerebral blood vessel intervention, a capillary vessel image is very useful to determine whether treatment is complete. In general, an X-ray computed tomography apparatus (X-ray CT apparatus) generates a capillary vessel image data set by using, for example, the technique disclosed in Jpn. Pat. Appln. KOKAI Publication No. 10-11604. More specifically, an X-ray CT apparatus performs threshold processing for volume data set generated by itself using an absolute threshold based on CT values to separate an artery/vein region (a region containing an artery region and a vein region) and a capillary vessel region. Then the apparatus extracts a capillary vessel region. And then the apparatus generates a capillary vessel image data set based on the extracted capillary vessel region. However, in a hospital having no X-ray CT apparatus installed in a manipulation room where intervention is executed, it is necessary to move a patient from the manipulation room to a CT room where an X-ray CT apparatus is installed. This is cumbersome for both the patient and the technician.
If an X-ray diagnosis apparatus (angiography apparatus) can generate capillary vessel image data sets, it is possible to save such cumbersome movement of a patient. The contrast of volume data set generated by an X-ray diagnosis apparatus is unstable as compared with that of volume data set generated by an X-ray CT apparatus because of various reasons (e.g., arterial injection of a contrast medium and a dose). The X-ray diagnosis apparatus cannot therefore perform the same processing as that performed by the X-ray CT apparatus (the separation of an artery/vein region and a capillary vessel region using the absolute threshold based on CT values). For this reason, arteries and veins interfere with the observation of perfusion in cerebral vessels using the X-ray diagnosis apparatus, resulting in a deterioration in observation accuracy.